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6. Consequences of corneal confocal microscopy
6.1 Generate more morphometric data for better definition
of normal cornea
6.2 Detect early changes before clinical disease or side
effect occur
6. Consequences Of Corneal Confocal Microscopy
6.1
Generate More Morphologic and Morphometric Data For Better Definition of
Normal Cornea
Confocal microscopy has, in many fields of research, contributed much to our understanding of the three-dimensional arrangement of structures, thus helping us to understand function which depends on spatial arrangement. The cornea, being a highly transparent tissue, is the ideal object to study tissue in the living individual. As these optical properties of the cornea are also crucial for its physiological optical function, any relevant corneal disease is quite likely to be detected with confocal microscopy at an early stage.
The histological structure of the cornea has been known since
microscopy has been invented. However, the layers of this tissue are oriented
parallel to the surface, so that for a histological evaluation of the three-dimensional
arrangement as well as for the description of all kinds of corneal disease,
a system of tangential sections is more appropriate. Only recently, semi-thin
sections parallel to the surface have helped to elucidate aspects of the
spatial organization of all layers of the cornea and their functional interdependence.
In the living eye, the application of specular microscopy has long ago
become a clinical routine method to evaluate the epithelial and endothelial
surface. In this respect, real time flying slit confocal microscopy has
achieved the visualization of all corneal layers with high resolution,
which detects subcellular details of much less than one micron diameter.
The application of confocal microscopy has provided us a tool to study
the morphology of normal corneal tissues, giving additional differentiated
information on the definition of "normal" in corneal layers previously
thought to be more or less homogeneous. With future standardization of
data collection, storage, and processing, the definition of normal will
be much more differentiated than we ever expected before.
6.2
Detect Early Changes Before Clinical Disease / Side Effect Occur
When we started to routinely practice confocal microscopy in larger numbers of patients and volunteers, our initial interest like that of other groups were focused on the further resolution of corneal disease detected by slit lamp biomicroscopy. As may have been expected, these gross corneal changes were too high in reflectivity, thus their intense signal masked all other signals in their vicinity. In these corneas, if one shifted the focus of the confocal microscope to areas that were not involved in slit lamp biomicroscopy, details previously not visible of the disease process were detected. Investigating clinically normal corneas in long term contact lens wearers, where we detected pathological findings that were not known previously, we realized that the stronghold of the confocal microscope will be the detection of very early or previously unknown disease. In other words, slit lamp biomicroscopy and confocal microscopy are methods which do not really overlap, but instead extend the range of what can be visualized in the cornea like low power and high power magnifications in a routine light microscope. Using both methods as a clinical routine, in the future we will be able to detect known pathologic processes at a much earlier stage and possibly also add new findings to the scope of pathological morphology of the cornea.
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